title: Plasma exchange therapy for thrombotic thrombocytopenic purpura in pediatric patients with liver transplantation.
abstract: OBJECTIVE
  Sporadic cases of thrombotic thrombocytopenic purpura (TTP) have been reported in bone marrow and solid organ transplant patients receiving cyclosporine (CsA). We reported our experience with TTP using plasma exchange (PE) therapy in patients with liver transplantation (OLT).
  
  
  METHODS
  Between March, 1993, and May, 2007, 400 patients underwent OLT, including 146 pediatric living-donor liver transplantation (LDLT). Four pediatric patients developed TTP after OLT: three were males and one female of mean age at the time of transplantation of 7.8 +/- 3.6 years. The four recipients had the following indications for OLT: two glycogen storage disease, one biliary atresia, and one fulminant hepatic failure. Four patients initially received triple drug immunosuppression consisting of CsA, azathioprine, and steroids.
  
  
  RESULTS
  Four (1%) patients developed TTP after OLT. All four patients were pediatric in the age group. The mean age at the time of TTP diagnosis was 8.0 +/- 3.2 years, with a mean postoperative interval to TTP of 78.8 +/- 114.2 days. The mean baseline platelet count was 7.0 +/- 7.1 x 10,000. The eventual platelet count was 21.1 +/- 20.8 x 10,000 after PE. These patients received PE 6.0 +/- 4.2. The mean baseline serum creatinine was 0.8 +/- 0.8 mg/dL. The mean peak serum creatinine was 2.3 +/- 2.3 mg/dL. The mean serum CsA level was 717.5 +/- 106.0 ng/mL before TTP diagnosis. Four patients were diagnosed by blood peripheral smears. The causes of TTP were CsA-associated in three patients and venoocclusive disease (VOD) in one patient. Three patients improved their platelet counts after PE therapy. Two patient changed from CsA to FK 506, one underwent reduced CsA dosage, and one stopped CsA. Three patients died of recurrent VOD, infection, and intrapulmonary hemorrhage. Only one patient survived.
  
  
  CONCLUSIONS
  The incidence of TTP in our series was lower. It only developed in pediatric patients. The causes of TTP were associated with CsA and/or VOD. The mortality was high after the TTP diagnosis. We concluded that TTP was a potentially fatal condition, but an early diagnosis with prompt institution of therapy with invasive PE therapy may reduce its mortal consequences.
authors.affiliation: Division of Nephrology, Liver Transplant Program, Chang Gung Memorial Hosptial-Kaohsiung Medical Center, Chang Gung University College of Medicine, Taiwan.
authors.forename: C-H
authors.initials: CH
authors.lastname: Lee
authors.forename: C-L
authors.initials: CL
authors.lastname: Chen
authors.forename: C-C
authors.initials: CC
authors.lastname: Lin
authors.forename: C-H
authors.initials: CH
authors.lastname: Yang
authors.forename: Y-F
authors.initials: YF
authors.lastname: Cheng
authors.forename: M-C
authors.initials: MC
authors.lastname: Wang
authors.forename: H-L
authors.initials: HL
authors.lastname: Eng
authors.forename: P-P
authors.initials: PP
authors.lastname: Liu
authors.forename: F-R
authors.initials: FR
authors.lastname: Chuang
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D006504:Hepatic Veno-Occlusive Disease / Q000628:therapy; D006801:Humans; D008107:Liver Diseases / Q000145:classification / Q000601:surgery; D016031:Liver Transplantation / Q000009:adverse effects*; D008297:Male; D010951:Plasma Exchange / Q000379:methods*; D011183:Postoperative Complications / Q000453:epidemiology / Q000628:therapy; D011697:Purpura, Thrombotic Thrombocytopenic / Q000628:therapy*; D012189:Retrospective Studies